‹ Portland, Maine weather by month
Typical May weather
Portland, Maine
Maine · May
64° days
46° nights
about 7 rainy days · 14½ hours of daylight · ocean 50°
What to pack
- Sweater
- Umbrella
What May feels like
May is lilacs and an Eastern Promenade full of people, but the Gulf of Maine warms on its own schedule and swimming remains for the committed. It's a damp month with plenty of grey mornings, so don't plan every single day outdoors.
Rain arrives about 7 days of the month, so keep one flexible day in your plans.
Can you swim?
The ocean runs about 50° — frigid — locals in wetsuits only.
The numbers
| Typical high | 64° |
|---|---|
| Typical low | 46° |
| Days with real rain | 7 |
| Total rain | 3.7 in |
| Humidity | dry air |
| Water temperature | 50° |
| Sunrise / sunset (mid-month) | 5:15 am / 7:59 pm |